Bore mining machine with strata differentiating device



July 9, Y1957 J. w. HEIMASTER 2,798,710 lBoRE MINING MACHINE WITH STRATA DIFEERENTIATING DEVICE FC c (lvcccfci /yv/f N* l E i N lNvEN-roR g JOHN W. HEIMASTER "'AVTTORNEY July 9, l957A l, J. w. HEIMASTER 2,798,710 v BORE MINING MACHINE WITH STRAT DIFFERENTIATING DEVICE?` med m. 2, 1954 s sheets-sheet 2" CONSTANT voLTAGE-b' In Conirol House SOURCE V 52hI t c M5 5U l A 30 22 Z3 f2 2322 5g;

v @EZ V 4 INVENTOR. -JOHN W.HEI`MASTER July 9, 1957 I J. w. HEIMASTER 2,798,710

. EOEE MINING MACHINE NITE STRAIN DIEEEEENTIATING DEVICE Filed Dec. 2, 1954 v s sheets-sheet s INVENTOR 4# JOHN w. HEMASTER y I l I BY ATTORNEY United States Patent O BDRE lvllNlNG lt/iAClzflINE WITH S'I'RATA DFFERENTATHNG DEVICE John W. Heimaster, Charleston, W. Va., assigner to Union Carbide and Carbon Corporation, a corporation of New York Application December 2, 1954, Serial No. 472,552

9 Claims. (Cl. 262-7) This invention relates to earth strata cutting-hardness indicating means, and more particularly to a strata differentiating device for remotely controlled bore-mining systems of the type disclosed in application Serial No. 353,- 932, filed May 1l, 1953, by Paul L. Alspaugh, Roy L. McNeill and myself.

According to the present invention there is provided a bore-mining machine that is equipped with a forwardly inclined strata splitting or cutting member such as a substantially non-vibratory blade the degree of tilt of which changes with the relative hardness of the stratum being cut by such blade as the machine advances. Such tilt is transmitted to a rheostat in an electrical circuit that includes a meter for indicating the degree of such tilt and, hence, the relative hardness of the stratum being cut by the blade. Thus, should the blade tend to depart from a selected stratum of coal, for example, and be rejected by sandstone or slate, for example, such fact is indicated at once to the operator. Obviously the invention can be applied to or used with any suitable mining or tunneling machine, although it is especially suitable for coal strata bore-mining machines that are remotely controlled.

More particularly there is provided according to this invention an earth strata differentiating device comprising a strata bore-cutting and mining machine provided with a head pivoted thereto for adjustment about a transverse axis for changing the vertical course of the machine, and at least one scarng or strata-splitting substantially nonvibratory member such as a chisel mounted at the top of the head for scarfng selected stratum from the roof of a bore-hole being made by the machine as the latter advances in making such bore-hole, the chisel being inclined upwardly and forwardly and free to tilt within upper and lower limits about a transverse axis that is generally parallel to such strata. The chisel is biased by yieldable means toward its upper limit in which position the cutting edge thereof is effective in scarng selected stratum from the roof of such bore-hole, and, at the same time, is positionally most sensitive to any increase in hardness of the material being or about to be scarfed thereby in that the chisel tends, by virtue of such hardness increase, to be tilted downwardly about such axis against the up- Ward force of such biasing means. Any downwardrtilt of the chisel is indicated at once to the operator by appropriate electromechanical indicating means.

Such indicating means preferably comprises a voltage source, a potentiometer the input ofV which is energized by such voltage source, mechanical means connecting the strata scarfing or cutting member to the potentiometer for changing the output thereof as such member is tilted, and a voltmeter connected to be energized by the output of the potentiometer. Suitable means are provided for cork trolling the machine from a control station located outside of such bore-hole, the voltrneter being located at such control station for continuously indicating to the operator of the machine the nature of the stratum such as the relative hardness thereof in the door or roof of the bore-holebeing made bythe machine.

chine illustrating the invention in a bore-hole being made` by such machine in theearth which is shown in cross-sec tion;

Fig. 2 is a fragmentary top plan view of such machine in the bore-hole, lthe earth strata being cut by such machine being shown in `cross-section;

Fig. 3 is an enlarged fragmentary view in side elev'ation of the strata differentiating device;

Fig. 4 is an enlarged fragmentary top plan view of such device, parts being broken away and shown in` section;

Fig. 5 is a view mainly in section taken on lineiS-S of Fig, 4;

Fig. 6 is a fragmentary front elevational view of the mining machine;

Fig. 7 is a simplified circuit diagram; and

Figs. 8-12 are fragmentary diagrammatic views in side elevation illustrating the principle of operation of the invention.

As shown in the drawings, the head 8 of a bo`r`e`-min ing machine 10 is equipped with transverse top and bottom cutter blades 12 and 14 which cut or scarf the small segments or cusps of coal left between the rotary cutters 16. The bottom cutter blade 14 is fixed, while the up'- per blade 12 is mounted to tilt within limits about a transverse axis 18, the bade 12 being held in its upper position by oil pressure within hydraulic cylinders 20, 20 which also inhibits the blade from vibrating in use. Oil `to the hydraulic cylinders is supplied at a selected constant pressure by conventional oil pump means incorporated in oil reservoir 21M. Normally the oil pressure urges the piston to the limit of its movement, so that the cylinder head 2Gb acts as a stop therefor, thus fixing thenormal cutting position of the blade `12. These blades, which have chisel-pointed teeth 22 `located in slots provided therefor in the cutting edge 23 of each blade, receive their cutting force from the forward motion of the machine 10. The chisel-pointed teeth 22 are of such shape and are held against the coal at such an angle as to provide the most effective strata cutting action.

The effective oil pressure in the hydraulic cylinders 2lb is kept such that the chisel-pointed teeth will cut coal 24, for example, but will refuse to penetrate any harder material 26. Thus, if an effort is made to raise the head 8 of the machine 10, the upper cutter blade 12 rises with such head 8 if it is cutting coal, but it refuses to rise when it encounters the harder material 26, and tilts down against the resistance of the oil pressure in the hydraulic cylinders 2t). Similarly, if the selected stratum or seam 24 dips downward, so that the blade 12 engages harder material over the coal which the chisel-pointed teeth 22 will not enter, the cutter blade 12 also tilts down.

Any downward tilt of the upper blade 12 is used to inform the operator that seam departure is irninent. The tilting motion of the upper blade 12 is converted into an electrical signal which is registered by a meter 30. Upon receiving such signal, the operator immediately makes the necessary course correction, which may beY either manual or automatic, without incurring any delay in the forward motion of the machine 10.

The system used to pick up and transmit such intelligence includes a cam 32 welded to an upper cutter blade hinge element 34 of which there are two, each pivotally connected to an arm 33 on the top of head S. Such cam engages a cam follower 36 which compresses a spring 38. As the upper cutter blade 12 is tilted down the cam 32 `is rotated around the axis 18 but is kept in contact with the follower 36 by the spring 38. A rack 40 integral with the follower 36 moves a pinion `42 which, inturn, transmits its motion through keyed shafts` 44 and `46 to a rheostat or potentiometer 48. The latter is `p`ro tected by a box-like cover 49. Such motion is indicated by the meter 30 at the control station. A guide pin Sil serves as a mechanical stop to prevent overtravel of the potentiometer shaft 46 and also as a lrey to prevent accidental rotation of the cam follower 35.

The'input of potentiometer 48, Fig. 7, is connected by suitably insulated conductors 52 and S4 to a constant voltage source 56; and the output thereof is connected by Isimilar conductors 57 and 58 to the meter 36 which, in this case, is a voltmeter. Thus, a change in the angular p position of the blade 12 due, for example, to an increase in hardness of the earth material being cut by such blade, is immediately indicated by the meter 3@ by virtue of the operation of the potentiometer 48 by such movement of the blade 12..

The principle of operation of the strata differentiating device of this invention is, as shown in Figs. S42. as follows:

If, Fig. 8, by using a cold chisel 60 with a small radins point 62, a force P is applied in line with the strata to a massive piece of laminar material 64, the chisel point e?. penetrates the material 64 only a short distance before the resistance to compression of the material (represented by components R14-R2), balances the force P, making the condition static.

But, Fig. 9, when distance L2 is many times less than distance L1 and the same force P is applied to such material, very different results are obtained. The thin lower section 66 of material then, due to the wedge-shape of the chisel 60, fails in bending along the plane X--X.

However, Fig. l0, after the clLsel point 62 penetrates the material a short distance, the resistance R1 to crushing in the material 68 above plane X-X is so rnuch greater than the upward component, Rz, that the point 62 is deflected downward. By adding a force represented by ,spring 70 to balance such difference the chisel 60 can be held on its course along plane X-X, Fig. l. l.

It would be an inefficient operation to part the material 64 along plane X--X with a chisel in the manner shown in Figs. 8-11, because the heel of the chisel must continuously crush the material. But, by inclining the chisel, as shown in Fig. l2, the effective shape of the chisel is changed and the heel resistance is eliminated, leaving lonly the horizontal components of forces R1 and R2 to be overcome by force l. The top face '74 of the chisel is relieved to give clearance and to exclude any frictional drag. This change in effective shape does not aifect forces R1 and Rz, however.

if the material above plane X-X should be harder than the material below such plane, the downward component of force R1 increases, while resistance R2 remains constant. When the dilference between such components exceeds the force exerted by the spring '70 the chisel point 62 is forced downward. Conversely, when the material above plane X-X is softer than the material below such plane, the chisel point 62 is forced upward.

This principle is utilized to operate the strata differentiating device which turn is used to guide the mining machine in the coal seam Z4. if the material below the parting plane X-X is coal and that 26 above the plane is shale, slate, or some other material harder than coal, 'such conditions are simulated.

While the device of this invention has been found highly suitable for use with remotely controlled mining machines to indicate at a remote station when contact has been made with a stratum of material of dierent hardness than the material being mined, and while it has been described in combination with such particular' machine, it will be apparent that the invention is not limited to such except as claimed below.

I claim:

l. A strata differentiating device comprising the comi bination of a strata scarng member pivotally mounted to a supporting structure, means urging said member angularly about its pivot against a stop, meansvfor advancing such structure generally parallel to the strata being scarfed by said member, said urging means resisting relative angular movement of said member away from such stop in response to the relative hardness of such strata, and indicating means responsive to such angular movement.

2. A strata differentiating device comprising the combination with a machine, and means for driving said machine along a path extending generally parallel to the strata to be ditferentiated, of `a strata splitting substantially non-Vibratory member pivoted to said machine for limited tilting movement about a transverse axis that is substantially parallel to such strata, said member extending forwardly in the direction of movement of said machine and being inclined between such axis and the strata; biasing means urging said member toward such strata and normally against a stop in a stationary position with respect to said machine as long as the relative hardness of the stratum being cut by such member does not change, the force of said biasing means being such that a change in such hardness relatively tilts the member in response thereto; and electro-mechanical means for indicating such relative tilt as soon as it occurs during the forward movement of said machine.

3. A strata differentiating device comprising the combination with a machine, and means for driving said machine along a path extending generally parallel to the strata to be differentiated, of Ia strata splitting substantially non-vibratory blade pivoted to said machine for limited tilting movement about a transverse axis that is substantially parallel to such strata, said blade extending forwardly in the direction of movement thereof with said machine and being inclined between such axis and the strata, `strata-splitting chisel-pointed teeth mounted along the forward-cutting edge of said blade, biasing means urging said blade toward such strata and normally against a stop in a stationary position with respect to said frame as long as thc relative hardness of the `stratum being cut by such teeth does not increase, the force of said biasing means being such that it can be overcome by an increase in such hardness which relatively ytilts the blade in response thereto, and electromechanical means for indicating such tilt as soon as it occurs during the forward movement of said machine.

4. An earth strata differentiating device comprising a strata bore-cutting machine provided with a head pivoted to the front thereof, a substantially non-vibratory member mounted at the top of'said head for scarng selected stratum from the roof of a bore-hole being made by said machine as the latter advances in making such bore-hole, said member being free to tilt within upper and lower limits about a. transverse axis, and being inclined upwardly and forwardly, means biasing said member against a stop at its upper limit in which position 'the cutting edge thereof is effective in scart-lng selected stratum from the roof of such bore-hole, and, at the `same time, is positionally most sensitive to any increase in hardness of the material being scarfed thereby in that said member tends by virtue of such hardness increase to be tilted downwardly about such axis against the upward force of such biasing means, and indicating means responsive to any downward tilt of said member.

5. An earth strata differentiating device as defined by claim 4, in which said indicating means comprises a voltage source, a potentiometer the input of which is energized by `said voltage source, mechanical means connecting said member to said potentiometer for changing the output thereof as said member is tilted, and a voltmeter connected to be energized by the output of said potentiometer.

6. An earth strata differentiating device as dened by claim 5, in which means are provided for controlling said machine from a control station located outside of such bore-hole, Iand said voltmeter is located at such control station.

7. In a remotely-controlled strata mining system, the

combination with a self-propelled coal cutting and mining machine having a head pivoted to the front end thereof for controlling 4the vertical course of such machine, of means for continuously indicating the relative hardness of the strata in the roof of the bore-hole being made by such machine, comprising a roof scarng substantially non-vibratory member pivotally mounted on the top of said head and being inclined upwardly and forwardly for cutting coal from such roof as the machine advances in such bore-hole, stop means for limiting the angular movement of said member, means urging said member upwardly against said stop means, and electro-mechanical means for continuously indicating the relative angular position of said member comprising a meter located at a control station for said machine.

8. In a remotely controlled strata mining system as defined by claim 7, means also located at said station for controlling the angular position of said head in accordance with the infomation supplied by said meter.

9. The combination with a selected earth strata boremining machine provided with front rotary cutters that leave a cusp Itherebetween in the strata being mined, of

CTI

means for mining such cusp to recover a substantial amount of wanted material and simultaneously indicating when such cutters are about to enter another strata of different hardness than that being mined, comprising a strata cutting blade pivotally carried by said machine in such a way that the blade projects outwardly and forwardly thereof in the Adirection of advance of the machine for mining such selected earth strata cusps, means providing a stop to limit the outward pivotal movement of the said blade and means urging said blade against said stop, said blade being responsive to the turning pressure thereon when a strata of different hardness is engaged thereby, and means for indicating such turning pressure in excess of a predetermined value.

References Cited in the file of this patent UNITED STATES PATENTS 1,915,001 McKinnon June 20, 1933 2,281,960 Vacquier May 5, 1942 2,694,562 Snyder et al Nov. 16, 1954 2,699,328 Alspaugh et al Jan. 11, 1955 

1. A STRATA DIFFERENTIATING DEVIC COMPRISING THE CONBINATION OF A STRATA SCARFING MEMBER PIVOTALLY MOUNTED TO A SUPPORTING STRUCTURE, MEANS URGING SAID MEMBER ANGULARLY ABOUT ITS PIVOT AGAINST A STOP, MEANS FOR ADVANCING SUCH STRUCTURE GENERALLY PARALLEL TO THE STRATA BEING SCARFED BY SAID MEMBER, SAID URGING MEANS RESISTING RELATIVE ANGULAR MOVEMENT OF SAID MEMBER AWAY FROM SUCH STOP IN RESPONSE TO THE RELATIVE HARDNESS OF SUCH STRATA, AND INDICCATING MEANS RESPONSIVE TO SUCH ANGULAR MOVEMENT. 